Extensible Markup Language (XML) has attained wide popularity in recent years. XML is a universal language that provides a way to identify, exchange, and process various kinds of data. For example, XML is used to create documents that can be utilized by a variety of application programs on computer of different manufacture.
To ensure that computer application programs understand the content of an XML document, an XML schema may be used to define the structure, content, and semantics of the XML document. Typically, the XML schema is identified in the XML document by a namespace, which is a unique identifier of the XML document's type. A namespace is typically identified by a Uniform Resource Identifier (URI).
With conventional systems, when a computer application program attempts to open a new or an existing XML document that is identified by a URI, the computer application program must somehow determine how it should handle the document. For example, the computer application program must decide how the XML document should be displayed, what types of behaviors the document should have, and where the XML schema associated with the document is located so that it can ensure the document's validity. In order to locate resources for handling the XML document in the conventional systems, the computer application program may look for pointers in the document, or prompting the user for information. These extra steps create delays and require undue effort by the user. Furthermore, the steps would likely have to be repeated when the computer application program encounters another document of the same type or when documents of the same type are encountered by another computer application program running on the same computer. Moreover, unsophisticated user may be confused when prompted for resources such as an XML schema.